The invention concerns an apparatus for the volumetric metering of fluid, pasty and/or powdery substances--in particular for separating small amounts of substance from a delivery flow--by means of an concerns uses of the apparatus.
In the industrial area the measured quantitative addition of amounts of substances is effected in various ways and always involves measurement, control and regulating procedures. Thus solid substances are generally metered in accordance with weight or numbers of items, liquid substances are metered using through-flow measuring devices or metering pumps on the basis of volume, and gaseous substances are metered with flowmeters.
Conventional apparatuses for metering fluid, pasty and powdery substances or agents are so designed that the operation of ascertaining the amount involved is effected in a comparatively complicated manner and with only relative accuracy. That applies in particular to metering installations for small amounts, as occur for example in the pharmaceutical or chemical industry; for the metering operation, it is a matter of crucial importance that the installations used can be easily and quickly cleaned, which however is possible only to a limited extent with the apparatuses available on the market. The known apparatuses also scarcely afford the required degree of constancy in terms of the amounts which are measured off or metered. Deviations--and therewith inaccurate amounts--frequently occur, for which reason the known metering apparatuses can give rise to problems in for example metering vaccination substances with a sufficient degree of accuracy; hitherto such substances have generally been metered into ampoules by hand.
In consideration of that state of the art, the inventor set himself the aim of providing an apparatus of the kind set forth in the opening part of this specification for the reliable metering of small to very small amounts of substance, in other words, increasing the reproducible metering accuracy therefor. The invention further seeks to provide for enlarging the area of use of metering apparatuses.